UK to Build $477M SG-1 Fantom Underwater Drone Factory with Helsing to Hunt Submarines

The United Kingdom is advancing its maritime defense capabilities through the construction of a $477 million facility dedicated to producing AI-powered underwater drones known as SG-1 Fantom gliders. This initiative, led by German defense technology firm Helsing, is part of a broader strategic response to increasing underwater threats, particularly from Russia. The facility, located in Plymouth, is expected to begin operations later in 2025 and will serve as a cornerstone of the UK’s efforts to enhance underwater surveillance and infrastructure protection.

SG-1 Fantom. Helsing

The SG-1 Fantom gliders represent a significant evolution in underwater monitoring technology. Originally developed for marine biology applications such as whale tracking, these autonomous vehicles have been repurposed for defense through the integration of the Lura artificial intelligence system. This system enables the gliders to detect and classify underwater acoustic signatures with high precision, reportedly up to forty times faster than traditional sonar operators. The gliders are designed to operate silently, propelled by ocean currents rather than engines, which makes them difficult to detect and suitable for long-duration missions of up to three months.

Each SG-1 Fantom measures approximately 195 centimeters in length and weighs around 60 kilograms. Despite their compact size, they are equipped with sonar and a suite of sensors that allow for continuous environmental scanning. Upon detecting a target, the glider surfaces and transmits data via satellite communication to command centers. This process enables real-time situational awareness and supports coordinated responses to potential threats.

The decision to invest in this technology aligns with broader trends in naval defense, where autonomous systems and artificial intelligence are increasingly used to supplement traditional platforms. The UK’s deployment of SG-1 gliders reflects a strategic shift toward distributed, passive surveillance networks capable of covering vast maritime areas. These systems are particularly relevant in light of recent incidents involving Russian submarines near British waters and undersea infrastructure, which have heightened concerns about covert underwater activity.

The manufacturing facility in Plymouth is part of a £350 million investment under the Trinity House agreement between Berlin and London. It is described as the UK’s first national resilience factory, aimed at bolstering sovereign manufacturing capacity for defense technologies. The project is also tied to the recommendations of the Defence and Economic Growth Taskforce, a collaboration between government, industry, and financial institutions. This taskforce has emphasized the importance of leveraging defense investments to stimulate economic growth and create high-skilled jobs across the country.

Helsing’s UK managing director has indicated that the initial production run will include hundreds of SG-1 units, with plans to scale up to thousands. These gliders are expected to be supplied not only to the British Royal Navy but also to allied navies facing similar underwater threats. The modular design and relatively low production cost of the SG-1 make it suitable for large-scale deployment, offering a cost-effective solution for persistent underwater surveillance.

The SG-1 program complements other autonomous underwater initiatives in the UK, such as the Cetus Extra Large Autonomous Underwater Vehicle (XLAUV) developed by MSubs. While the SG-1 focuses on passive surveillance and acoustic detection, platforms like Cetus are designed for broader missions, including experimentation with new technologies and support for crewed submarines. Together, these systems represent a layered approach to underwater defense, combining stealth, endurance, and advanced data processing.

The UK’s investment in AI-powered underwater drones marks a significant development in maritime security strategy. By integrating autonomous systems with artificial intelligence, the Royal Navy aims to enhance its ability to monitor and protect critical underwater infrastructure. The SG-1 Fantom gliders, with their low observability and advanced detection capabilities, are poised to play a central role in this effort, reflecting a broader shift toward innovative, data-driven approaches in naval defense.